On a beautiful afternoon, William rode his bicycle to a farm that sold baskets of watermelons for $5.96 each and baskets of apples for $9.21 each. William decided to buy a basket of watermelons and a basket of apples because those were his favorite kinds of fruit. How much did William need to pay for his produce?
Answer: To find the total amount William needs to pay, we need to add the price of the watermelons and the price of the apples. Price of watermelons + price of apples = total price. ${5}$ ${9}$ ${6}$ ${9}$ ${2}$ ${1}$ ${+\vphantom{0}}$ ${7}$ ${1}$ ${5}$ ${1}$ William needs to pay $15.17.